Light emitting devices such as LEDs (Light Emitting Diode) have high energy efficiencies and are therefore used in light emitting devices to save energy. In particular, white-light illumination with high efficiency and high luminous flux have been subjects of attention. In white-light illumination, for example, a blue LED is used to emit blue light which is then transformed to other wavelengths by phosphors to synthesize white light.
The blue light emitted from blue LEDs is easily absorbed by various members, including a substrate on which the LED is mounted. Configurations have therefore been considered in which materials such as silver that have a high reflectance at a wavelength of blue light are used to reflect the blue light to the exterior. Silver is a high-value material and deteriorates easily, and so there are particular limits on where silver can be used.
For example, a configuration is known in which the reflectance of a sub-mount where the light emitting device is to be mounted is set greater than that of an interconnection unit of the substrate. However, no specific configuration is known for a useful light emitting device equipped with a plurality of high-power semiconductor light emitting elements.